In this kind of artificial limb, it is necessary to know correctly in what state or phase it is, because the correct knowledge ensures an appropriate controlling operation. Reviewing an artificial leg, for example, it is important to know in what phase the artificial leg is, i.e., whether it is in a swing phase or stance phase, or whether it is in a level walking or hill walking. The load and moment, as well as a knee angle, which are taken as an agenda in this invention, are important factors to find out such phases. Although an artificial leg will be described hereinafter as an object to which the present invention is applied, the present invention is, as a matter of course, likewise applicable to any artificial limb.
A first method for measuring or detecting a load (or force in an axial direction) and moment is to detect the load and the moment independently. Patent Documents 1 and 2 show such a first method. A second method is to obtain a mixed information of the load and moment all together, then separate such obtained mixed information by calculation and obtain each information of the load and the moment. Patent Document 3 shows the second method. The first and second methods are based on such an assumption that a detection device including a sensor block and a strain gauge is built in an artificial limb and the detection device itself is used as one component part of the artificial limb as generally practiced.
Separately from the technique in which the detection device is used as a component part of the artificial limb, another technique is also known in which a detection device is temporarily built in an artificial limb, then analysis and evaluation (evaluation whether it is well fit to the wearer) with respect to the artificial limb are performed, and thereafter, the detection device is replaced with a predetermined component part (for example, rotary adapter) of the artificial limb. Patent Document 4 shows the technique in which a detection device is temporarily built in an artificial limb.